BEIRUT, May 14 (Reuters) - The leader of Lebanon’s powerful Hezbollah group, Sayyed Hassan Nasrallah, said on Monday a missile attack from Syria into the Israeli-occupied Golan Heights last week marked a new phase in the Syrian war.

Israel has said the attack was carried out by Iran’s Revolutionary Guards, which set up Hezbollah in 1982. Shi’ite Hezbollah is fighting in Syria in support of President Bashar al-Assad.

In a televised speech Nasrallah said the rocket attack showed Syria and its allies are ready to go to “the greatest extent” to defend Syria from Israel. He did not say who had carried out the attack.

Nasrallah said 55 missiles were launched from Syrian territory in the attack. Israel had said 20 missiles were shot down by its Iron Dome defence system in the attack on Thursday. (Reporting by Tom Perry and Laila Bassam; Writing by Lisa Barrington; Editing by Andrew Roche)